Delta Air Lines, Inc. is a major American airline, with its headquarters and largest hub at Hartsfield–Jackson Atlanta International Airport in Atlanta, Georgia. The airline along with its subsidiaries operate over 5,400 flights daily and serve an extensive domestic and international network that includes 334 destinations in 64 countries on six continents, as of June 2015. Delta is one of the four founding members of the SkyTeam airline alliance, and operates joint ventures with: Air France-KLM and Alitalia; Virgin Atlantic; and Virgin Australia. Regional service is operated under the brand name Delta Connection.